Prior to permanently coupling an implanted medical electrical lead to the corresponding implantable pulse generator, an evaluation of sensing and/or stimulation efficacy is typically conducted to assure that electrodes and/or other types of sensors and/or therapy delivery members of the implanted lead are properly positioned. External medical devices, for example, pace sense analyzers (PSA) or neurological screeners, depending upon the type of lead and therapy delivery, are typically employed to carry out these implant evaluations. These medical devices include electrical connection cables that have contact members for making a temporary electrical connection with connector contacts of the implanted lead. The lead connector contacts are typically formed on a proximal connector terminal of the implantable medical electrical lead, which connector terminal extends out from the patient's body prior to coupling with the implantable pulse generator. Many lead connector terminals are formed with connector contact surfaces that are of sufficient size and spacing to accommodate relatively simple and reliable temporary connection with typical contact members, such as the alligator-type clip and the j-type clip known in the art, which are employed by the aforementioned connection cables. However, in the interest of increasing lead functionality by multiplying the number of therapy delivery members (i.e. electrodes) carried by the lead without unduly increasing the size/bulk of the lead, some connector terminals are of a more compact design/form (i.e. reduced connector contact surface area), which can compromise the relative ease and reliability of making these temporary electrical connections. One such connector terminal design/form is dictated by a relatively new international standard, ISO/FDIS 27186:2009(E), commonly known as the IS-4 standard, for four-pole connector terminals of cardiac pacing and defibrillation leads. Various adapters designed to couple with IS-4 connector terminals, and the like, in order to provide an enhanced interface that facilitates temporary electrical connection with external medical devices for lead implant evaluation, are known in the art, for example, as described in commonly-assigned U.S. Pat. No. 7,130,699. However, there is still a need for new adapters that are designed to provide a more robust interface for these temporary connections, without compromising ease of use and lead integrity.